Pion elastic and charge-exchange scattering on p-shell nuclei by isobar-doorway state model

The purpose of the present paper is to extend the isobar-hole model (i.e., the conventional isobar-doorway state model for the pion-nucleus reaction, to open-shell nuclei) by reformulating the model, and also to study the ela stic scattering of pions from p-shell nuclei, the analyzing power and the c harge-exchange reaction. For this purpose, we use the projection operator f ormalism, and take into account the correct center-of-mass transformation a nd the off-shell behavior of the pion-nucleon scattering amplitude. We assu me a realistic nuclear model, i.e. the p-shell nuclear model of Cohen and k urath;. By studying elastic scattering from C-12,C-13 and N-15, and the ana lyzing power and the charge-exchange reaction with 13C and N-15, We confirm the existence of the Lane term in the spreading potential implied by Hirat a ct al.